Process control systems, such as those used in chemical, petroleum or other processes, generally include a centralized process controller communicatively coupled to one or more field devices which may be, for example, valve positioners, switches, sensors (such as temperature, pressure and flow rate sensors), etc. These field devices perform physical control functions within the process (such as opening or closing a valve), take measurements within the process for use in controlling the operation of the process, or perform any other desired function within the process. Generally speaking, the process controller receives signals indicative of measurements made by one or more field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals which are sent via the buses to the field devices to thereby control the operation of the process.
Information from the field devices and the controller is usually made available over a data highway to one or more other hardware devices, such as operator workstations, personal computers, data historians, report generators, centralized databases, etc., typically placed in control rooms or other locations away from the harsher plant environment. These hardware devices run applications that may, for example, enable an operator to perform functions with respect to the process, such as changing settings of the process control routine, modifying the operation of the control modules within the controllers or the field devices, viewing the current state of the process, viewing alarms generated by field devices and controllers, simulating the operation of the process for the purpose of training personnel or testing the process control software, keeping and updating a configuration database, etc.
With digital based control and communication, information pertaining to a device or an application (such as a software program) may be made available to a user or operator in some standardized format within the control programming environment. For example, the information may be made available to the user via a uniform resource locator (URL) or hyperlink that provides an automatic link or connection to further documentation or a further application. The URL or hyperlink may be embedded in computerized documentation for a process control element corresponding to the device or application, such as within the description field of the process control element. With the URL or hyperlink, a user or an operator can easily access related documentation or a related application for the process control element by merely selecting the URL.
Additionally, the hyperlink or URL may include a generalized field. When the hyperlink or URL is selected, the generalized field may be replaced with some information pertaining to the process control element, such as the name or location of the process control element or the name of a containing element (such as a process area or a node) of the process control element. In this manner, process control elements may be copied, renamed and changed without having to change the URL(s) provided in the documentation associated therewith.
Current URLs and hyperlinks that are associated with process control elements in a process control system, however, are generally statically defined. That is, current URLs or hyperlinks must be defined in the process control system during configuration. If a new or modified URL or hyperlink is desired, a re-configuration or download must occur for the new or modified URL to be accessible within the process control system.
Moreover, not only does a statically defined URL or hyperlink require definition during configuration, but it also requires a separate definition for each separate instance of occurrence of the corresponding process control element. For example, a static URL may defined to link a specific standard operation procedure (SOP) document to a specific device in a first display view, but additional static URLs must be each separately defined and configured in order to link the same SOP to the same specific device for all other display views that include the specific device.